Merge pull request #6881 from nikhiljindal/errHandle

Registering a serviceErrorHandler with go-restful to always return JSON responses

pkg/api/errors/errors.go

@@ -250,7 +250,7 @@ func NewTimeoutError(message string, retryAfterSeconds int) error {
 }
 
 // NewGenericServerResponse returns a new error for server responses that are not in a recognizable form.
-func NewGenericServerResponse(code int, verb, kind, name, serverMessage string, retryAfterSeconds int) error {
+func NewGenericServerResponse(code int, verb, kind, name, serverMessage string, retryAfterSeconds int, isUnexpectedResponse bool) error {
 	reason := api.StatusReasonUnknown
 	message := fmt.Sprintf("the server responded with the status code %d but did not return more information", code)
 	switch code {
@@ -297,6 +297,17 @@ func NewGenericServerResponse(code int, verb, kind, name, serverMessage string,
 	case len(kind) > 0:
 		message = fmt.Sprintf("%s (%s %s)", message, strings.ToLower(verb), kind)
 	}
+	var causes []api.StatusCause
+	if isUnexpectedResponse {
+		causes = []api.StatusCause{
+			{
+				Type:    api.CauseTypeUnexpectedServerResponse,
+				Message: serverMessage,
+			},
+		}
+	} else {
+		causes = nil
+	}
 	return &StatusError{api.Status{
 		Status: api.StatusFailure,
 		Code:   code,
@@ -305,13 +316,7 @@ func NewGenericServerResponse(code int, verb, kind, name, serverMessage string,
 			Kind: kind,
 			ID:   name,
 
-			Causes: []api.StatusCause{
-				{
-					Type:    api.CauseTypeUnexpectedServerResponse,
-					Message: serverMessage,
-				},
-			},
-
+			Causes:            causes,
 			RetryAfterSeconds: retryAfterSeconds,
 		},
 		Message: message,

pkg/apiserver/apiserver.go

@@ -30,6 +30,8 @@ import (
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/admission"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	apierrors "github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/latest"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/meta"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/rest"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/healthz"
@@ -168,6 +170,15 @@ func InstallLogsSupport(mux Mux) {
 	mux.Handle("/logs/", http.StripPrefix("/logs/", http.FileServer(http.Dir("/var/log/"))))
 }
 
+func InstallServiceErrorHandler(container *restful.Container) {
+	container.ServiceErrorHandler(serviceErrorHandler)
+}
+
+func serviceErrorHandler(serviceErr restful.ServiceError, response *restful.Response) {
+	// TODO: Update go-restful to return the request as well, so that we can use the appropriate codec rather than using the latest one.
+	errorJSON(apierrors.NewGenericServerResponse(serviceErr.Code, "", "", "", "", 0, false), latest.Codec, response.ResponseWriter)
+}
+
 // Adds a service to return the supported api versions.
 func AddApiWebService(container *restful.Container, apiPrefix string, versions []string) {
 	// TODO: InstallREST should register each version automatically
@@ -246,6 +257,7 @@ func writeJSON(statusCode int, codec runtime.Codec, object runtime.Object, w htt
 		return
 	}
 	w.Header().Set("Content-Type", "application/json")
+	glog.Infof("Writting status code: %d", statusCode)
 	w.WriteHeader(statusCode)
 	w.Write(formatted.Bytes())
 }

pkg/client/request.go

@@ -792,7 +792,7 @@ func (r *Request) transformUnstructuredResponseError(resp *http.Response, req *h
 		message = strings.TrimSpace(string(body))
 	}
 	retryAfter, _ := retryAfterSeconds(resp)
-	return errors.NewGenericServerResponse(resp.StatusCode, req.Method, r.resource, r.resourceName, message, retryAfter)
+	return errors.NewGenericServerResponse(resp.StatusCode, req.Method, r.resource, r.resourceName, message, retryAfter, true)
 }
 
 // isTextResponse returns true if the response appears to be a textual media type.

pkg/master/master.go

@@ -431,6 +431,7 @@ func (m *Master) init(c *Config) {
 
 	apiserver.InstallSupport(m.muxHelper, m.rootWebService)
 	apiserver.AddApiWebService(m.handlerContainer, c.APIPrefix, apiVersions)
+	apiserver.InstallServiceErrorHandler(m.handlerContainer)
 
 	// Register root handler.
 	// We do not register this using restful Webservice since we do not want to surface this in api docs.